The decommissioned Coast Guard 625-foot-tall LORAN tower in the Sconset section of Nantucket will be taken down piece by piece over the next week.

Contractors will disassemble what was once the longest continuously-operated LORAN station in the world.

Work got underway on the project this week, when contractors hired by the Coast Guard’s civil engineering unit in Providence arrived on Nantucket.

Built on Nantucket at the height of World War II, the LORAN station had been a part of the island for more than six decades, and a critical navigation tool for mariners and aviators before it was decommissioned in 2010.